Collect. Czech. Chem. Commun.
1994, 59, 1624-1636
https://doi.org/10.1135/cccc19941624
X-Ray Absolute Structure of Nicergoline (Form I). Quantitative Analysis of Nicergoline Phase Mixture: Form I/Form II
Michal Hušáka, Jiří Hadb, Bohumil Kratochvíla, Ladislav Cvakc, Josef Stuchlíkc and Alexandr Jegorovd
a Department of Solid State Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6, Czech Republic
b Central Laboratories, Prague Institute of Chemical Technology, 166 28 Prague 6, Czech Republic
c Galena Co., R. & D., 747 70 Opava-Komárov, Czech Republic
d Galena Co., Research Unit, Branišovská 31, 370 05 České Budějovice, Czech Republic
Abstract
The structure of semisynthetic ergot derivative nicergoline (form I) was determined from X-ray single crystal diffraction data. The title alkaloid (10α-methoxy-1,6-dimethylergoline-8β-methanol-5'-bromonicotinate, C24H26BrN3O3) crystallizes in the triclinic space group P1, with a = 7.729(7), b = 8.695(4), c = 17.030(8) Å, α = 100.90(4), β = 98.67(5), γ = 93.04(5)°, Z = 2. A structural comparison of nicergoline forms I and II was made. The quantitative analyses of some model phase mixtures form I / form II were carried out using both Rietveld full profile fitting method and linear regression of the peak intensity concentration dependence. Results obtained are in good mutual agreement. The smallest limit of detection of form II in binary mixture with form I is about 3% as found from powder diffraction study.
